Study On Anode Bond Mechanism And Thermal Stress Of LAZS Glass-ceramics/Stainless Steel

Anodic bonding is one of the most important technologies in microelectromechanical systems(MEMS)packaging technology,and has been widely used because of its simple process,high packaging efficiency and good packaging quality.With the application of micro-systems and large-scale integrated circuits more and more widely,the application environment is more and more challenging,so the performance of the device itself and structural requirements become more stringent.In the packaging process some of the traditional materials have been insufficient to meet the current development needs of MEMS,while the quality of the package is often due to the difference between the thermal expansion coefficient of materials caused by thermal failure and reduce device life and reliability.In view of this phenomenon,this study based on the selection the glass-ceramic materials which has characteristic in mechanical strength,high hardness,chemical stability,thermal stability,especially its thermal expansion coefficient can be adjusted within a wide range.It can be used instead of traditional glass,silicon,borosilicate glass for anodic bonding with metal materials.To provide a theoretical basis and technical support for solving the thermal failure problem.Aiming at the problem of thermal failure of glass-ceramic and stainless steel,In this paper,MSC.Marc finite element analysis software was used to analyze the residual stress distribution produced by the temperature during the bonding cooling process.The ratio of the bond thickness between the glass-ceramic and the stainless steel is changed by 1:1,1:2,1:3,1:4,1:5,1:6.The results show that when the ratio of the thickness of the glass-ceramic and stainless steel the residual stress is smaller,and the maximum residual stress is mainly distributed on the surface of the material.When the area ratio is vary byl:1,2:1,3:1,4:1,5:1,6:1,the smaller the ratio of the area of the glass-ceramic and stainless steel is,the maximum residual stress value tends to be a stable value.The main reason for this change is the change caused by the change in the heat conduction mode.It can be concluded that the structure has a crucial effect on the residual stress distribution during the bonding process.The optimum thickness area ratio is helpful to reduce the adverse effects of stress when selecting other factors such as the stiffness of the material when selecting the bonding structure.This article studies its bonding mechanism and through the finite element software to optimize the residual stress distribution,In this paper,LAZS glass-ceramic with matching thermal expansion coefficient of 430#stainless steel was prepared by using the whole crystallization method.Through the 430#stainless steel surface magnetron sputtering silicon thin film transition layer to ease due to the direct bonding of stainless steel and glass-ceramics residual stress is too large bonding failure problem.XRD,SEM and EDS measures were used to analyze the phase composition,microstructure and energy spectrum of 430#stainless steel and LAZS glass-ceramic bonded interface.The results show that the migration of metal ions in the alkali metal ions and anode materials during the bonding process is the most basic condition for the formation of the interfacial transition layer.The interfacial layer of lithium oxide is the key to bond bonding.The source of oxygen ions is not from the fixed oxygen in the main crystalline phase of lithium silicate,but from the free oxygen of the residual glass phase.The effect of different alkali metal ions on the bonding strength of the interface layer.The depth of the diffusion layer is proportional to the square of the time and time.